Claude Fable 5.1 vs Union Alpha
Specs, per-token pricing, and live benchmark scores — refreshed daily from our benchmark database.
Specs & pricing
| Claude Fable 5.1 | Union Alpha | |
|---|---|---|
| Company | Anthropic | Stealth |
| Released | Sep 2026 | Sep 2026 |
| Context window | 1.0M | 262K |
| Input /1M tokens | $10 | free |
| Output /1M tokens | $50 | free |
| Open weights | No | No |
Benchmarks
| Benchmark | Claude Fable 5.1 | Union Alpha |
|---|---|---|
| GPQA | 93.7% | — |
| Speed (tok/s) | 70 tok/s | — |
Scores come from published leaderboards and official model cards (sources listed on the benchmarks page) and refresh daily. Pricing via vendor pages and OpenRouter.